The Collaborative International Dictionary of English v.0.48:

closing \closing\ n.
   1. the act of closing something.

   Syn: shutting.
        [WordNet 1.5]

   2. the last section of a communication.

   Syn: conclusion, close, ending.
        [WordNet 1.5]

   3. termination of operations.

   Syn: closure, closedown, shutdown.
        [WordNet 1.5]

   4. a concluding action.

   Syn: completion, culmination, windup, mop up.
        [WordNet 1.5]

   5. (Commerce) the final action in a commercial transaction,
      especially the meeting between buyer and seller (and in
      some cases mortgagee), or their representatives, in a
      transaction for sale of real estate in which all documents
      are signed and all procedures carried out to complete the
      sale; -- called also real estate closing.
      [PJC]